The present invention relates to an improvement in pads for use with shoulder straps. The use of straps extending across one shoulder to carry luggage, camera and computer equipment, large purses and a wide variety of other items is commonplace. While such straps are convenient as they free the user's hands, they quickly become uncomfortable, particularly with heavier loads, and continually tend to slide off the user's shoulder. These problems result from the fact that peoples'shoulders are not square but somewhat rounded and slope downwardly in varying degrees from the base of the neck to the point of the shoulder and from the shoulder's apex to the upper chest and back region. Shoulders are also typically thicker proximate the neck area than at the outer point of the shoulder. Thus, the weight of the shoulder bag or other object being carried by a flat strap causes the inner portion of the strap proximate the neck to tend to "dig" uncomfortably into the shoulder and the strap to slide down and off the shoulder.
The discomfort and sliding problems experienced with shoulder straps are compounded by the fact that the user's hip and waist regions prevent an object carried from a shoulder strap from hanging directly under the area of the shoulder against which the strap bears. The object is forced outwardly from such area so that the strap hangs at an outward declination, increasing the angle of inclination of the strap on the shoulder and thereby limiting the effective area of the strap which is pulled downwardly against the shoulder to the portion of the strap adjacent its inner edge. Concentrating the load of the object carried by the strap to such a narrow portion thereof and thus to a very small area of the shoulder, increases both the discomfort in the shoulder and the tendency of the strap to slide off the shoulder. The wider the load carried by the strap, the more the strap declines outwardly from the shoulder and the more acute these problems become.
Considerable effort has been expended in attempting to solve these problems and a wide variety of shoulder pads and anti-slip devices have been developed for use with shoulder straps. While providing some improvement over a bare uncushioned strap, such devices have not proved successful in solving these problems and in many cases have created additional problems.
The most commonly employed solution to the discomfort problem is simply to provide a soft cushioned pad for the strap which typically includes a plurality of slits or loops through which the strap may be inserted to secure the pad onto the strap. While providing some cushioning between the strap and the shoulder, such pads do not address the angular relationships between the contours of the user's shoulder and the shoulder strap hanging thereacross at a slightly outward declination. As a result, the pad bears against the shoulder predominately along the inner edge portion of the pad and the weight of the load is still transmitted to the shoulder over a very small area. Because of the concentration of the load on the shoulder, the cushioning effect of the pad is relatively ineffective and discomfort quickly results and increases with time. In addition, these cushioned pads tend to slide back and forth along the strap, requiring frequent adjustment. To attach many of such pads to a shoulder strap it is first necessary to detach one end of the shoulder strap from the object being carried which often is not possible with many bags fitted with shoulder straps.
Many of these cushioning pads are comprised of a plurality of materials, typically including a lower soft layer and a stiff upper layer or layers. Such composite pads are not only more expensive to manufacture but have a tendency to tear or separate at the junctions of the different materials and at locations where the strap is extended through or between the materials comprising the pad. Again, such composite pads have not addressed the angular relationship between the strap, the pad and the shoulder. As a result, these cushioning pads have not provided an adequate solution to the discomfort created by shoulder straps. They are also often awkward to use, frequently tend to deteriorate prematurely and do relatively little to address the problem of holding the strap in place on the user's shoulder.
The most commonly employed solution to the slippage problem is to provide a pad having a non-uniform lower surface provided with projecting ridges or small spiked-like projections which increase the friction between the pad and the user's clothing. The angular relationship between these pads and the user's shoulder again inhibits their effectiveness in holding the strap in place. Such pads still tend to slide down the user's shoulder, pulling on his or her shirt and making such devices uncomfortable to use.
Wedge-shaped pads have also been developed in an effort to provide a horizontal base for the shoulder strap and thereby reduce the tendency of the strap to slide off the user's shoulder. Examples of such devices are found in U.S. Pat. Nos. 4,887,318 and 5,250,345. While reducing somewhat the tendency of the strap to slide off the shoulder, such devices do not solve the problem. As noted above, the anatomical configuration of the human form does not allow a bag to hang from a shoulder strap directly under the area on the shoulder in contact with the bag. The hips and waist areas force the bag outwardly, causing the shoulder strap to extend both downwardly and outwardly. Thus, even when a horizontal platform is provided for the strap, the vector forces generated by the outward disposition of the bag continue to tend to pull the bag outwardly along the downward slope of user's shoulder. In addition, these directional forces cause the inner edge portion of the strap to bear against the pad more forcefully than the mid and outer portions of the strap. Accordingly, only a narrow portion of the pad absorbs the great majority of the weight of the bag. As a result, the horizontal base does little to spread the concentration of the load carried by the strap over a larger portion of the shoulder. Thus, the discomfort associated with shoulder straps is not appreciably relieved by the use of wedge-shaped pads.
The contoured pad of the present invention provides a solution to both the discomfort and slippage problems discussed above. By configuring the pad such that it contours the strap in the shoulder area so as to mate with the contour of the shoulder and projects therefrom at an outward declination toward the object carried by the strap, the entire width of the pad effectively absorbs the weight of the load carried by the strap and transmits that load to a larger area of the shoulder. As a result the concentration of the load on the shoulder and the discomfort resulting therefrom are significantly diminished. In addition, such a contour tends to maintain the strap in place on the shoulder. The shoulder pad of the present invention obtains these results without the need for bulky padding or joined multiple materials and is of economical construction and readily secured in place on the shoulder strap.
These results are achieved in the present invention by configuring the shoulder pad such that it defines a continuous convex arcuate strap support surface periodically interrupted by one or more upstanding projections defining apexes adjacent the outer edge of the support surface for elevating isolated portions of the strap at an outward inclination above adjacent portions of the support surface. A plurality of strap retention members hold the shoulder strap against the portions of the strap support surface adjacent the projections so as to force the strap against the projections and cause the strap to incline outwardly and laterally about each of the projections. In so doing, the strap turns outwardly on the support surface about each of the projections. By imparting such inclined turns into the strap, the pad of the present invention effectively contours the portion of the strap extending over the support surface defined by the pad to the outer surface of the user's shoulder and redirects the strap from the ends of the pad at an outward declination toward the object carried by the strap. To provide a more even distribution of the load on the strap across the shoulder pad, the projections therein are preferably defined by inclined wedges in the strap support surface transversing adjacent portions thereof. Such a configuration provides a continuous support surface for the strap as it turns thereon over the user's shoulder.